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Isolation of Pulmonary Artery Smooth Muscle Cells from Neonatal Mice
Published on: October 19, 2013
Pulmonary capillary recruitment in neonatal lambs
L J Means1, W L Hanson, K O Mounts
1Department of Anesthesia, Indiana University School of Medicine, Indianapolis 46202-5120.
Pediatric Research
|November 1, 1993
Summary
Newborn lambs do not recruit lung capillaries when pulmonary arterial pressure rises, limiting gas exchange reserve. Older lambs show significant capillary recruitment, indicating developing gas exchange capacity with lung maturation.
Area of Science:
- Physiology
- Pulmonary Medicine
- Neonatal Research
Background:
- Increased pulmonary arterial pressure typically redistributes blood flow to the upper lungs, recruiting capillaries and enhancing gas exchange.
- It remains unclear if this capillary recruitment occurs in young animals with underdeveloped lungs.
Purpose of the Study:
- To investigate capillary recruitment in the upper lungs of neonatal and older lambs in response to elevated pulmonary arterial pressure.
Main Methods:
- In vivo microscopy was used to directly observe capillary perfusion in individual alveolar walls.
- Pulmonary arterial pressure was elevated using airway hypoxia in neonatal (<10 days old) and older (20-61 days old) lambs.
Main Results:
- In neonatal lambs, hypoxia increased pulmonary arterial pressure but did not lead to capillary recruitment.
- In older lambs, hypoxia increased pulmonary arterial pressure and resulted in a significant increase in recruited capillaries (46%).
Conclusions:
- Capillary recruitment does not occur in newborn lambs with increased pulmonary arterial pressure, suggesting limited gas exchange reserve.
- Lung maturation in older lambs leads to the development of gas exchange reserve through recruitable capillaries.
